A Marketing Cloud admin needs to warm their accounts Dedicated IP.

Segment by domain to limit number of sends to each email provider is the option for segmentation that aligns with the IP Warming process. IP Warming is the process of gradually increasing email volume from a new or unused IP address to build trust and credibility with Internet Service Providers (ISPs). Segmenting by domain means dividing the email list into smaller groups based on the email domain, such as gmail.com or yahoo.com. By segmenting by domain, marketers can limit the number of sends to each email provider and avoid being flagged as spam or blocked by the ISPs.